Paper coated with an anti-abrasive compound



United States Patent 3,210,211 PAPER COATED WITH AN ANTI-ABRASIVE COMPOUND Harry E. Dunholter, Toledo, 'Ohio, assignor to Owens- Illinois Glass Company, a corporation of Ohio No Drawing. Filed July 13, I962, Ser. No. 209,795 8 Claims. (Cl. 117154) This invention relates to improvements in non-abrasive coating compositions, to the method of coating paper products therewith, and to the coated paper products so formed.

More specifically, this invention relates to improvements in softening compositions for paper products used to make container packs, to the method of coating paper products therewith, and to the coated paper products so formed.

In the packaging of certain articles in paperboard containers, such as kraft linerboard, it has been noted that the articles have suffered from abrasion by contact with the paperboard surfaces of said containers. Illustrative of such articles are bowling balls, painted metal motors, and furniture having a highly polished surface. The abrasion to these articles, which occurs as a result of vibration in transit and rough handling, is due to the rubbing of untreated cellulose fibers in the paperboard containers against the surfaces of the aforementioned articles.

Accordingly, it is an object of this invention to provide a novel composition for softening these cellulosic fibers of these paper products and thereby render them nonabrasive.

A further object of this invention is to provide paper products having surfaces which have been softened and as a result are substantially non-abrasive.

A further object of this invention is to provide methods for imparting a non-abrasive surface to paper products.

Still further objects and advantages of this invention will become apparent from the following description and the appended claims.

The objects of this invention are attained by coating a paper product, such as kraft linerboard, with a water solution of an alkali metal salt of a monobasic acid ester of isethionic acid.

In general, the alkali metal salts corresponding to the following structure were found to be admirably suited for softening the surfaces of linerboard used in making containers:

(l) UH3 (CH2)n %f O CH2 CH2 SO3 R I wherein n is an integer from 6 to 16 and M is an alkali metal selected from the group consisting of sodium, potassium and lithium. One method of making an alkali metal salt of the isethionic acid ester is disclosed in US. Patent In this connection the following monobasic acids can be employed in preparing the isethionates of formula (1) above:

Structure: Name CH (CH COOH Caprylic acid. CH (CH COOH Pelargonic acid. CH (CH COOH Capric acid. CH (CH COOH Lauric acid. CH (CH COOH Myristic acid. CH (CH COOH Palmitic acid.

Stearic acid.

In general, monobasic acids having from 8 to 18 carbon atoms can be satisfactorily used to form the desired alkali metal isethionates.

3,210,211 Patented Oct. 5, 1965 A further understanding of the processes and products of this invention will be better obtained from the following examples which are intended to illustrate the invention but not to limit the scope thereof, parts and percentages being by weight.

Example 1 Sodium lauroylisethionate was applied to the wire side of 42 pound kraft linerboard by means of rollers, namely, a flexographic applicator, from a 1 to 10 solution of the isethionate to water at a temperature of about 190 F. so as to obtain a solid deposit of about 1.3 pounds per 1,000 sq. ft. (M s.f.) of liner board. The coated linerboard was then dried. It was thereafter noted that the container made with 42 pound kraft linerboard treated in this manner did not mar or scratch the hard rubber surface of a bowling ball shipped therein, whereas untreated 42 pound kraft linerboard heavily scratched the same surface.

Example 2 Procedure of Example 1 was repeated except that the ratio of isethionate to water was 3 to 10 at a solid deposit of about 2 pounds per M sf. of kraft linerboard. In this instance, the treated linerboard prevented scratching of an enameled metal surface at room temperature, whereas untreated linerboard seriously marred a similar enameled surface.

For purposes of testing the effectiveness of the antiabrasive composition of the present invention, the composition was subjected to the following accelerated aging test. The solution of Example 2 was applied to the wire side of 42 pound kraft linerboard so as to provide a solids pickup on the linerboard surface of approximately 3.0 pounds per M s.f. The linerboard was then heated to F. for 72 hours. An article having an enameled metal surface was thereafter placed in a container made from kraft linerboard treated in this manner and the article was observed to be neither scratched nor marred.

Although for some applications it will be found that only about 1.3 pounds per M s.f. will be required, it has been noted that the best results are obtained in preventing scratching or marring of articles packaged in containers coated with the isethionates of the present invention if the solids pickup on the linerboard is approximately 3 to 4 pounds per M s.f. In addition, the water solution should preferably be relatively hot when applied, namely, from about F. to about 200 F.

It will be apparent to those familiar with the art that other coating equipment can be employed to apply the isethionate composition to the container paper so as to prevent the scratching or marring of articles packaged therein. For example, in addition to the flexographic rollers, it will be evident that other rollers, such as rotogravure rollers, can be effectively use to apply the isethionate composition to the linerboard.

In addition, other changes and modifications can be made in the coating compositions and processes described herein as will be obvious to those skilled in the art without departing from the spirit and intent of this invention. Moreover, it is to be understood that the examples set forth are to be taken as illustrative only and are not limiting in any sense.

I claim:

1. A paper product having at least one surface coated with a substance corresponding to the following structure:

wherein n is an integer from 6 to 16 and M is an alkali metal selected from the group consisting of sodium, potassium and lithium, said substance being present in an amount of about 1.3 to 4 pounds per thousand square feet so as to soften the surface of said paper product and render it non-abrasive.

2. A paper product having at least one surface coated with a substance corresponding to the following structure:

said substance being present in the amount of about 1.3 to 4 pounds per thousand square feet so as to soften the surface of said paper product and render it non-abrasive.

3. A paper product having at least one surface coated with a substance corresponding to the following structure:

said substance being present in the amount of about 3 to 4 pounds per thousand square feet so as to render it nonabrasive.

4. A process of softening paper products so as to render them non-abrasive comprising applying to at least one surface of said products an aqueous solution of a compound corresponding to the following structure:

wherein n is an integer from 7 to 16 and M is an alkali metal selected from the group consisting of sodium, potassium and lithium, said substance being applied to said products in an amount of about 1.3 to 4 pounds per thousand square feet of said compound so as to soften the surface of said paper products, and thereafter allowing said paper products to dry.

5.. A process of softening paper products so as to render them non-abrasive comprising applying to at least one surface of said products an aqueous solution at a temperature of about 180 F. to 200 F. of a compound corresponding to the following structure:

said substance being present in the amount of about 1.3 pounds per thousand square feet so as to soften the surface of said paper product and render it non-abrasive.

'7. A paper product having at least one surface coated with a substance corresponding to the following structure:

said substance being present in the amount of about 3 to 4 pounds per thousand square feet so as to soften the surface of said paper product and render it non-abrasive.

8. A paper product having at least one surface coated with a substance corresponding to the following structure:

wherein n is an integer from 6 to 16 and M is an alkali metal selected from the group consisting of sodium, potassium and lithium, said substance being present in an amount of about 3 to 4 pounds per thousand square feet so as to soften the surface of said paper product and render it non-abrasive.

References Cited by the Examiner UNITED STATES PATENTS 1,868,862 7/32 Washburn 117 154 1,881,172 10/32 Daimler et al. 260-400 2,066,542 1/37 Schrauth 260 400 2,268,674 1/42 Roth 117-154 2,342,563 2/44 Tucker 260-400 MORRIS LIEBMAN, Primary Examiner. 

1. A PAPER PRODUCT HAVING AT LEAST ONE SURFACE COATED WITH A SUBSTANCE CORRESPONDING TO THE FOLLOWING STRUCTURE: 